Refrigerating apparatus



June 3, 1941. P. E. Loomis v REFRIGERTING APPARATUS -Filed Dec. 24, 193ezwi/mon -Pzef 5 OMZS.

BY iw@ Patented June 3, 1941 UNITED STATE namesaa'rnva APPARATUS Petern. Loo

Borg-Warner Illinois minimum. nnen., asignar a) Corporation, acorporation I ci' Applicaties December za, 193s, serial No, 117,432

' (ci. ca -si m 8 Claims. l This invention relates to rei'rigeratingapparatus in general and has particular reference to improvements inreirigerating systems, to im` provements inthe elements or apparatusused therein, and to a system or method of andapparatus for producingrefrigeration either at a singletemperature orfat a plurality o!selected ,ditlerent temperatures at the same time. I.

The reirigerating system selected tor purposes of illustration includesan evaporator having two sections, one being disposed within the otherand separated therefrom, and the two as a unit contemplating thedisposal thereon/within a heat insulated compartment. The outsideevaporator section, namely, the box cooling coil, is adapted forproducing refrigeration, during normal operation, at a temperaturesimilar to' striction in the :passageway between the evapom ratorsections during single-temperature operation ofthe system but which ismanually operable to partially restrict said passageway so as to providea refrigerating system the evaporator sectionsof which are operable atdifferent pressures, and thus. diierent temperatures, when densing unitwhich itself includes a compressor that produced by the inner, orfreezing. evapora` tor section; this temperature is such that the lattersection keeps ice cubes in their frozen condition.` Of'the twoevaporator sections the outside section is the one having the moreconstant refrigerating eiect, operating within the limits of about 23 F.to 31 F., whereas the inner section is adapted for selective temperaturevariations, its operation being between, say, 5 F. and 27 F. 'I'hesystem, because of the food compartment of the cabinet being shieldedfrom the freezing section, during two-temperature operational thesystem'. is adapted to maintain a constantly high relative humiditywithin ,the

heat insulated compartment whereby the quality of the foods storedtherein will not be ieopardized by the low temperature of 'the innersection. It might be said at this time that the accumulator or headerfor the freezing section oi the evaporator contemplates the provisiontherein of a conventionaL means for returning the lubricant therefrom byentrainment. to the compressor through the system suction line, althoughthis means is not disclosed. Y,

' In adidtion to the two-section evaporator the system includes a valvewhich is adjustable 'i'or creating a pressure differential between thetwo Ior, say, keeping ice cream in its frozen condition. or forsingle-temperature operationin general.

The invention contemplates the use therein of any type of valve whichVprovides little orno reof any desirable type. Although undisclosed, thesuction pressure inlet port of the compressor is provided with a checkvalve which is adapted to maintain a difference in pressure between thesystem suction line and compressor suction chamber While\t he compressoris at rest. Associated with the condensing unit and the two-sectionevaporator, and disposed in the high pressure `feed line therebetween,and dividing the system into a high and low pressure side, is ahigh-side float valvelof the type known to the industry today. l

The principal object of the present invention is to, utilize in anordinary heat insulated cabinet an evaporator or heat absorbing meanshaving two sections, one of said sections being maintained betweenrelatively constant temperature limits during normal operation of thesystem, and the other of said sections being maintained with- Ainapproximately the same temperature limits 'during said normal operationoi the system, but

which may be independently subjected to a substantiallydower pressureaccording to the, wants of the operator, thereby producing therein acorrespondingly lower y temperature than in said former section.

Another object of this invention is to provide a system oi'refrigeration which normally operates at a unitary temperature, butwhich may be turned into a two-temperature refrlgerating sysv iscomprised of fewer working parts than systems at present used, therebyproviding a system which is not only simple and compact but alsoinexpensive in initial and operating costs.

Another object of this invention is to provide in a system ofrefrigeration an adjusting means adapted for association with thecooling and freezing coils ot the evaporator for operating the system asa whole at a unitary temperature durstantially independent of the other.

ing normal operation. thereof, or for operating the system as atwo-temperature system when so desired. '1

Another object of this invention is to provide' in conjunction with asystem of refrigeration eme paratus for performing same, which producesa,

plurality ofI different temperatures simultaneously with the productionof a plurality ofdifferent relative humidities, each temperature and itsc orresponding relative humidity representing the most favorableoperating conditions for the particular part of the apparatus in whichsame are produced, and each relative humidity being sub- Another objectof this invention is to provide in a single refrigerating system aplurality of evaporators or cooling coils separated from each other andhaving means therebetween for-selectively producing different suctionpressures so as to obtain different. temperature conditions in each ofsaid coils of the evaporator.

Other objects and advantages of the invention will be apparent from aconsideration of the following specication taken in conjunction with theaccompanying drawing of which there is Vone sheet and in which:

Fig. 1 is a diagrammatic view of a refrigerating system embodying theinvention herein disclosed;

Fig. 2 is a part sectional view taken along the lines 2-2 of Fig. 1 andshowing in detail a modification of the means utilized in Fig. 1 forproducing the optional singleor two-temperature rel frig'eration; and

Fig. 3 is a view taken along the lines 3-3 of Fig. l 2 and showing morein detail .the head of and' stop for the valve disclosed in Fig. 2.

In Fig. 1 there is illustrated a condensing unit, generally indicated atI0, adapted for supplying liquid refrigerant to the evaporators andremoving vaporous refrigerant therefrom. Unit I0 comprises a compressor,generally indicated at H, possessing an inlet port I2 (winch includes anundisclosed check valve) and a discharge port i8 to the latter of whichis cinnected a compressed refrigerant conduit I6 which develops` itselfinto a condenser, generally indicated at i8. Disposed effectively withrelation to condenser [I8 for dispensing with much of the heatsurrounding same is a blower unit 20 which is operated by the same means2l as that which, by a belt (not shown), drives the compressor il. Thecondensing unit I0 is suitably supported by means of a support 24.

Condenser I8 is operatively connected by a high side fluid feed line 26which includes therein a high side float valve, generally indicated at28. Valve 28 divides the system intoa low and a high pressure side andis an ordinary high side float valve which is well known tothe industryand comprises, in general, a oat 30 which is adapted to operateaccording to the quantity of uid passing through the valve. As soon asenough fluid is built up behind and within valve 28 to operate the float30, the valve opens and the high pressure fluid refrigerant is allowedto pass through the valve and into another section 232 of said line 26.The exposed portion of feed line 32 is heavily insulated to preventrefrigeration of the surrounding air, and loss of eiiiciency thereby,

vtogether along their edges to form a continuous shield which empty intoa series .of horizontally disposed headers 36. Coil 34 and headers38 areadapted for continuous circulatlonof fluid and partially vaporousrefrigerant therethrough.

Disposed within and shielded from the food compartment by the box coil34 is the shelf coil, generally indicated at 38, of the evaporator unit.One end of coil 38 is connected to a portion of the upper part of coll34 for fluid refrigerant communication therebetween. The other end ofshelf coil 38 is connected to an accumulator 40. Shelf coil 38 comprisesa plurality of. horizontally and vertically disposed tube sections whichare properly placed for heat exchange relationship between the tubesections and a plurality of shelves 42 on which ice trays may be placed.

To a portion of accumulator 40 which lies above the liquid level thereinis connected one end of the system suction line 44 the other end ofwhich is connected to the suction pressure inlet port I2 of compressorIl through a check valve to, is a coil spring 56 whichvis telescoped' bya collapsible bellows 58, said bellows being bonded or otherwise securedto a flange provided therefor on piston 54 'and to the forward end of.body member 50.` On the other side of piston 54 of valve 41, andadjacent thereto, is another coil spring 6l) which is oppositely andsymmetrically disposed with relation to the other spring 56, and isseated on a shoulder provided therefor on piston 54. .The end of spring68 which is opposite the piston 54 is adapted to rest againstashoulderprovided therefor in body member 50 and extending into bore 52.

Integral with and projecting from one side of piston 54 is a valve steml52 adapted for minute reciprocation relative to an opening 64 providedtherefor in body member 50. The end of valve stem 62 opposite the piston54 is.provided with an enlarged head 58, the under-portion of which isbeveled and adapted to define the inner circumference of an annularring-shapedvarea with one corner of the aforementioned shoulder of bodymember.50 defining the outerv circumference of said area when the valveis in its seated position. This ring-shaped area is one of the two meansfor providing a communication in the,

otherwise-restricted passageway between coils 3c and 38 when the valveis closed. The enlarged head 5S is provided with a still larger annularanged head 58 which is disposed in a bore 'it provided therefor in thebody member 5G.

The under-side .of flanged portion 55 of valve head S5 is adapted tobeseated on a series of radially projecting lugs 12 which are integralwith the body member 50 and extend radially into bore lll to such anextent as to provide a suitable seat for the flanged portion 58.. Itwill be seen that the diameter of portion 68 is lessthan the diameterofbore 10, and that the ring-shaped area defined between the wall ofbore 'l0 and the has thermally only by the Aspace the second aforetheotherwise revstricted passageway .between coils 34 and 38 when the valveis inl its seated position. 4

'I'he reason for providing a valve which-communicates the` refrigeranton either side thereof with the suction side of-.the compressor; evenwhen said valve is closed, is, of course, to enable the box coil to becontinuously operated at a temperature sufliciently can be stored in theheat insulated compartment and kept Without being frozen and, as well,without deteriorating. This temperature ranges between the limits, ashas already been said, of about 23 F. and 31 F., the box temperaturebeing keptin the -nelghborhood of, say, 35 F. and, no matter at what'temperature the shelf coil is being operated, these box coiltemperature limits will be maintained, since the valvel provided hereinoffers the same amount of communication therethrough regardlesslof howsecurely it is seated. In other wo'rds, this` system provides l arelatively constant'box coil temperature during normal or abnormalditions. e

Provided in the body member 50 and adapted for associating box coil 34with bore 10 and shelf coil 38 with bore 52, respectively, is a pair ofopenings 14 and 16. Coils 34 and 38 may be joined to body member 50 ofvalve 41 in any ppropriate manner such as by co-relation` betweenthreaded portions of the coils and threaded portions provided thereforin body member 5I).`

In order to close 4the valve mechanism from the atmospherethere isprovided a `heavy cap member 80 which is formed internally thereof toprovide a threaded bore 82 in which a valve adjustment handle 84(advisedly insulated) is adapted to be adjustably disposed. Opposite theelf coil.operating conhandle portion of member 84 there is provided aportion 86' which is adapted to be telescoped by one end of spring 56,said end of spring 56 being adapted to rest handle 84. Members 8l) and50 are joined to; gether, with the forwardly flanged portion of bellows58' interposed therebetween, by means of Va series of cap screws 90which into threaded ber portions provided therefor in mem- 50.` A hole92 is provided in member 84 and extends axially therethrough'l tocommunicate the against a shoulder portion 88 of extend through`openings Aprovided therefor in member 88 and The system described theabove paragraphs operates in the following manners:

low enough so that foods l heat of the fins. on the or two-temperaturesystem according to the wants of the operaton And, it must be rememberedthat the valve, when closed, should have a constantly open by-pass, and,when open, should provide as little restriction as possible to the fluidpassing therethrough.

A dial 94, or other form of indicating means, is y secured to the face.of cap member 88 adjacent the handle 84 and is provided with spacednumer als thereon showing the proper positions of haindle 84 forthecorresponding shelf temperatures.

In order to maintain I'the box cooling coil be' tween the aforementionedtemperature limits a.

thermostatic bulb 96 is secured to the coil and associated therewith athermally operated switch` 91 which is 'connected in 'series with theelectric current used to operate the compressor motivating means andconducted by conduits 88.

' the two .coils are low been frozen,

The vaporous refrigerant which is compressed let part I4, the conduitthe condenser I8 wherein the ensuing heat exchange causes the vaportoloondense. From condenser I 8 the'liquid refrigerant passes throughfeed line 26 and into oat va1ve28.. When enoughfluid comes in contactwith valve 28 to operate the float 30, the float opens and fluid isallowed to pass therefrom into and through the line 32. The fluid thenpasses into coil 34, into and through the open valve 41 and coil 38, andfills same upto a' varying level in accumulator 40. In the process of 34and 38 the refrigerant is evaporated, such action causing thetemperature of the refrigerant The gas which is formedl in both coils\tdrop; bythe evaporation, together with minute quantities of entrainedlubricant', pass from the accumulator 48 into and through the systemsucof the system, the

valve 41 is in its open position and both the box coil and the shelfcoil are maintained at practically Athe`same pressure. There is a slightdifference in temperature, however, between the two coils, and this`difference is caused by the affecting the shelf coil effect between itand because fof the shielding the box coil. The most economicaloperating condition is when the valve 1s in this open position and thetemperatures in enough to freeze water and to keep the ice cubes intheir frozen condition, but not low enough thekeep ice cream.

If it is desired to keep ice cream after it has or to otherwise have thesystem operate as a two-temperature apparatus, it is l necessary for theoperator to adjust the valve handle 84 of valve 41 so that the pressureon spring 58'will be relieved. The valve will then have its headpermanently seated, and the systemwill operate with the box coil andshelf coil.

In order to return to single-temperature operation, the operator must'turn handle 84 back to its original position so/that piston 54 totheright against the opposition of and l thereby head 88.

It is to be understood that the invention is not a normal operatingpressure in a much lower pressure in the spring 68 limited to the specicfeatures of the igures and systemdisclosed, but is vto be consideredbroadly as is represented by the scope of the appended claims. i

I claim: r

1. A cooling unit comprising an inner lwaporator section andan outerevaporator section enclosing the first mentioned section; a conduit forsupplying liquid refrigerant to said outer section and a secondconduitfor removing vaporized refrigerant from the inner section; meansfor con-` ducting refrigerant from one of said sections to the other; acontrol device interposedh'in said lmeans and comprising a valve membershiftable to one position to permit unrestricted flow of refrigerantfrom the outer to the inner sectionposition in which it cuts down suchand a manually operable element accessible .e

or to a second ow;

passing through the coilsl box coil, such heat notA is. forced 'vcausing the unseating of valve l 'v from the exterior of said nected tosaid valve member for shifting thel outer sectionand consame, saiddevice being constructed to permita flow of at least a predeterminedamount of 1refrigerant from said outer to said inner section at alltimes when said -unit is in operation.

2. In a refrigerating unit including an ice freezing compartment and afood cooling compartment, a'two-'section evaporator comprising afirstsection located in said freezing compartment and a second sectionlocated in said food cooling compartment, means connecting said tionwith said second section, said means being particularly characterized bythe provision' of manually adjustable pressure governing means forcontrolling the pressure in s aid evaporator sections, whereby saidsystem is convertible at will vwfrom or to a single temperature systeminto or from a two temperature system and means for supplying said firstevaporator with liquid refrigerant and for removing vaporous refrigerantfrom said second evaporator section.

3. In a refrigerating unit including an ice freezing compartment and afood cooling compartment, a two-section evaporator comprising a firstsection located in said freezing compartmentand a second section locatedin said-food first seccooling compartment, means connecting said iirstsection with said second section, said means being particularlycharacterized by the provision of manually adjustable pressure governingmeans for controlling the pressure in said evaporator sections, wherebysaid system is convertible at will from or to a single temperaturesystem into4 or from a two temperature system Aand means for supplyingsaid rst evaporator with liquid refrigerant and for 'removing vaporousrefrigerant from said ysecond evaporator section, said connecting meansbetween said evaporator sections being further particularlycharacterized byv the fact member formed with an internal borel saidbore being provided with a valve seat, said valve seat havinginterrupted portions, a reciprocable valve member having a firstposition in engagement with said seat providing for a limited passage offiuid thereby ybetween said valve and said interrupted seat,and a secondposition providing for substantially uninterrupted flow past said valve,and manual means for selectively moving said valve to either said firstposition or said second position.

PETER B. LOOMIS.

that the same comprises a body`

